/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev.jjs.impl;
import com.google.gwt.dev.jjs.ast.Context;
import com.google.gwt.dev.jjs.ast.JConstructor;
import com.google.gwt.dev.jjs.ast.JExpressionStatement;
import com.google.gwt.dev.jjs.ast.JMethodCall;
import com.google.gwt.dev.jjs.ast.JModVisitor;
import com.google.gwt.dev.jjs.ast.JNewInstance;
import com.google.gwt.dev.jjs.ast.JProgram;
import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
/**
* Removes calls to no-op super constructors.
*/
public class RemoveEmptySuperCalls {
/**
* Removes calls to no-op super constructors.
*/
public static class EmptySuperCallVisitor extends JModVisitor {
@Override
public void endVisit(JExpressionStatement x, Context ctx) {
if (x.getExpr() instanceof JMethodCall && !(x.getExpr() instanceof JNewInstance)) {
JMethodCall call = (JMethodCall) x.getExpr();
if (call.getTarget() instanceof JConstructor) {
JConstructor ctor = (JConstructor) call.getTarget();
if (JProgram.isJsTypePrototype(ctor.getEnclosingType())) {
// don't remove calls to JsType super-constructors;
return;
}
if (ctor.isEmpty()) {
// TODO: move this 3-way into Simplifier.
if (call.getArgs().isEmpty()) {
ctx.removeMe();
} else if (call.getArgs().size() == 1) {
ctx.replaceMe(call.getArgs().get(0).makeStatement());
} else {
JMultiExpression multi = new JMultiExpression(call.getSourceInfo());
multi.addExpressions(call.getArgs());
ctx.replaceMe(multi.makeStatement());
}
}
}
}
}
}
public static boolean exec(JProgram program) {
EmptySuperCallVisitor v = new EmptySuperCallVisitor();
v.accept(program);
return v.didChange();
}
}